Kristin Scott Thomas stars as Julia Jarmond, an American journalist in Paris who's writing a magazine article about the 1942 Vel' d'Hiv Roundup, in which the French police deported thousands of Jews to Nazi death camps. When Julia discovers that her French husband's family owns an apartment that belonged to victims of the roundup, she becomes obsessed with discovering their fate.

Shown in flashbacks, the story of 10-year-old Sarah Starzynski is powerful, thanks in large part to the luminous screen presence of young Mélusine Mayance. She embodies her character with a confidence rarely seen in child actors; she could be a French Dakota Fanning.

When the police come to arrest the family, quick-thinking Sarah coaxes her little brother into a closet and locks it. But after she and her parents are crowded into a Paris arena called the Vélodrome d'Hiver, it becomes horrifyingly clear that their detention is intended to be permanent.

Back in the present, Julia traces Sarah's quest to escape and return home to rescue tiny Michel. But while the flashbacks come to life through small acts of courage and kindness amid epic-scale evil, the frame story is a recurring letdown that feels trivial and contrived. Scott Thomas plays her role with conviction, but some preachy dialogue in the magazine office undercuts the emotions of the story, and the conflict with her workaholic husband is underdeveloped and not particularly interesting.

In these moments when the machinery of the narrative shows through the screen, de Rosnay's theme of the power of truth stumbles over the false notes of fiction.